Bioaccessibility and bioavailability of bioactive compounds from yellow mustard flour and milk whey fermented with lactic acid bacteria.

Microbial fermentation with lactic acid bacteria (LAB) is a natural food biopreservation method. Yellow mustard and milk whey are optimum substrates for LAB fermentation. The aim of the present study was to evaluate the bioaccessibility and bioavailability of bioactive compounds from yellow mustard flour and milk whey both with and without LAB fermentation. All extracts were subjected to a simulated digestion process. Total polyphenols, DL-3-phenyllactic acid (PLA), lactic acid, and the antioxidant activity were determined in the studied matrices before and after simulated digestion. Yellow mustard flour was significantly richer in total polyphenols, whereas significantly higher concentrations of PLA and lactic acid were observed in milk whey. Similar antioxidant activity was determined in both ingredients being in all cases strongly reduced after in vitro digestion. Higher bioaccessibility was found for polyphenols and PLA in milk whey. Transepithelial transport of total polyphenols was higher in yellow mustard flour compared to milk whey, reaching bioavailability values between 3-7% and 1-2%, respectively. PLA transepithelial transport was only significant in both fermented matrices with bioavailability around 4-6%. Transepithelial transport of lactic acid reached values of 31-34% (bioavailability ∼ 22%) and 15-78% (bioavailability ∼ 3%) in milk whey and yellow mustard flour, respectively. LAB fermentation showed beneficial effects on enriching extracts with PLA, lactic acid, and antioxidant activity, as well as increasing bioaccessibility of these acids in yellow mustard flour and total polyphenol bioavailability in milk whey. Results pointed to yellow mustard flour and milk whey as natural preservative ingredients used in the food industry, especially when fermented with LAB.

Whey fermented by using Lactobacillus plantarum strains: A promising approach to increase the shelf life of pita bread.

Nowadays, there is an increasing concern regarding the shelf life of food products, leading producers to research natural antimicrobial agents to use in food preparation. In this study, we evaluated the antifungal activity of Lactobacillus plantarum fermented whey and then added the whey during preparation of pita bread to study shelf-life improvement. The fermented whey showed a satisfactory inhibitory (antifungal) effect against Penicillium expansum and Penicillium brevicompactum strains: the minimum inhibitory and minimum fungicidal concentrations ranged from 3.9 to 39.0 g/L and from 62.5 to 250 g/L, respectively. Addition of fermented whey increased the shelf life of the pita bread. After inoculation of the bread surface with Penicillium, an increase in shelf life until d 8 was achieved compared with the positive control, whereas under natural contamination conditions, an extension of shelf life until d 19 was observed. In terms of antimicrobial activity, the greatest reduction (100%) in fungal growth was achieved when all of the water in the dough was replaced with fermented whey. An untrained sensory panel could not identify differences between bread produced with fermented whey and control pita breads. These results suggest the possibility of using fermented whey in food preservation.

Shelf life extension of mozzarella cheese contaminated with Penicillium spp. using the antifungal compound ɛ-polylysine.

Molds are one of the most important spoilage organisms on cheese which can lead to economic loss as well as raising public health concerns due to the production of mycotoxins. This study investigates the use of ɛ-polylysine as natural antimicrobial to inhibit fungal growth. The minimal inhibitory concentrations and minimal fungicidal concentrations of ɛ-polylysine were determined against Penicillium roqueforti, Penicillium nordicum, and Penicillium solitum. Then, polylysine was tested as surface antimicrobial for the preservation of mozzarella slice cheese inoculated with these Penicillium spp. and stored in plastic trays during 25 days. The minimal inhibitory concentrations calculated for the three fungi tested were of 60 mg/l whereas the minimal fungicidal concentrations detected were of 125-10,000 mg/l. The shelf life observed for the control experiments was of 15 days, and just using the ɛ-polylysine at 0.00625, 0.0125, and 0.025% was evidenced a shelf life increment in comparison with the control of 1-3 days.

Evaluation of biological and antimicrobial properties of freeze-dried whey fermented by different strains of Lactobacillus plantarum.

The aim of this study was to evaluate the biological and antimicrobial activities of commercial freeze-dried whey fermented by lactic acid bacteria in order to valorize this high polluting liquid waste of the dairy industry. Freeze-dried whey was fermented by different strains of Lactobacillus plantarum (CECT 220, 221, 748) at three different times of fermentation (24, 48, 72 h). Afterwards, the extract was purified on centricon amicon with a cut-off of 3 kDa to obtain a permeate consisting of small bioactive compounds reported in the literature to show greater bioactivity. The purified and diluted samples were subjected to the biological and antimicrobial tests for the evaluation of antioxidant, antihypertensive, iron binding, and antifungal activities and identification of phenolic compounds. The results highlighted a radical cation scavenging activity ranging from 1.415 to 2.083 mmol trolox equivalents TE per kg of dry weight, a percentage of iron binding capacity ranging between 23-55% and a percentage of ACE inhibitory activity ranging between 67-85%. The optimal biological activity was obtained from whey fermented by L. plantarum 220 for all the assays performed, except for the iron chelating activity. Furthermore, the antifungal analysis showed a good activity against the mycotoxigenic fungi belonging to Fusarium generum (F. moniliformis, F. graminearum and F. verticillioides), while a slight activity was obtained for Aspergillus and Penicillium generum. This antifungal activity could be correlated to the production of phenolic compounds during fermentation. The obtained results support the hypothesis of using whey as a functional ingredient to improve food preservation.

Antimicrobial packaging based on ɛ-polylysine bioactive film for the control of mycotoxigenic fungi in vitro and in bread.

ɛ-Poly-l-lysine (ɛ-PL) is a cationic peptide with a broad-spectrum antimicrobial activity. This study investigates the use of ɛ-PL as natural antimicrobial to inhibit fungal growth and to reduce aflatoxins (AFs) production. Antifungal activity of starch biofilms with different concentrations of ɛ-Poly-l-lysine (ɛ-PL) was determined in solid medium against Aspergillus parasiticus (AFs producer) and Penicillium expansum. Then, biofilms were tested as antimicrobial devices for the preservation of bread loaf inoculated with A. parasiticus CECT 2681 and P. expansum CECT 2278. Shelf life and AFs content were examined. Biofilms with concentrations of ɛ-PL less than 1.6 mg/cm2 showed no fungal growth inhibition in solid medium, while the antifungal activity of the films with greater than 1.6 mg/cm2 of ɛ-PL was dose dependent. The shelf life of bread inoculated with A. parasiticus was increased by 1 day with the use of films containing 1.6-6.5 mg ɛ-PL/cm2, while shelf life of bread tainted with P. expansum was increased by 3 day with 6.5 mg ɛ-PL/cm2. AFs production was greatly inhibited by ɛ-PL biofilms (93-100%). Thus, ɛ-PL biofilms could be potentially used as antimicrobial device during bread storage as a natural alternative to the synthetic preservatives. Practical applications: Ɛ-Polylysin is a natural substance from microbial metabolism. Polylysine has a function to prevent a microbe from proliferating by ionic adsorption in the microbe. ɛ-polylysine has a wide antibacterial spectrum and has an obvious lethal effect on Gram-positive and Gram-negative bacteria, yeast, mold, viruses, etc. It has a good antibacterial effect on the Gram-negative bacteria E. coli and Salmonellae, which are difficult to control with other natural preservatives. ɛ-Polylysine has already been used generally as a food additive in Japan, Korea and other part of world. In the United States, FDA has recognized the polylysine as a GRAS material. Considered the positive results obtained in the study, this compound could be used for the production of antimicrobial biofilms, applied as separator slices in the loaf bread production, to prevent the growth of the mycotoxigenic fungi A. parasiticus and P. expansum, contributing to reduce the use of the synthetically preservatives in bakery industry and also of the negative impact that these compounds could generate on the health of the end users.

Toxicity reduction of ochratoxin A by lactic acid bacteria.

Ochratoxin A (OTA) is a mycotoxin produced by the metabolism of fungus belonging to the genus Aspergillus and Penicillium. In this paper we report, the capacity of different cultures of lactic acid bacteria (LAB) to degrade OTA present in MRS broth at both pH 3.5 and 6.5. A study of OTA reduction during gastrointestinal digestion carried out with the LAB was also performed. Taking into account the two reduction mechanisms of OTA studied in this work as the enzymatic one and the adsorption on the cell wall, as well as at pH 3.5 and 6.5 the reduction values of OTA were in a range of 30-99%, being the strains with greater reduction (97% and 95%) Lb. rhamnosus CECT 278T and Lb. plantarum CECT 749 respectively. In the experiments carried out digesting the OTA in MRS medium with LAB, the highest bioaccessibility reduction was observed by the strain of Lb. johnsonii CECT 289, showing a mean reduction around all the gastrointestinal digestion process of 97.4%. The mass spectrometry associated to the linear ion trap method identified ochratoxin alpha (OTα) m/z = 256.1 and phenylalanine (Phe) m/z = 166.1 as the major metabolites of OTA degradation in LAB cultures.

Risk assessment of mycotoxin intake through the consumption of Spanish breadcrumbs / Evaluación del riesgo de ingesta de micotoxinas a través del consumo de pan rallado español

In this work, 80 commercial samples of breadcrumbs, purchased from different supermarkets located in Valencia (Spain), were investigated for the presence of 11 legislated mycotoxins. Only 9 samples evidenced the presence of the legislated mycotoxins. The compounds detected were: ochratoxin A (OTA), zearalenone (ZEA), T-2 toxin (T-2) and HT-2 toxin (HT-2). The incidence of OTA was of 3.75% with concentrations ranging from 1.50 to 6.75 µg/kg. One sample showed a contamination level higher than the maximum legislated in Europe for OTA. Three samples were contaminated with ZEA at concentrations varying from 64.32 to 449.21 µg/kg; all values were higher than the maximum allowed by the legislation. T-2 and HT-2 were detected in two (18.25- 2700.48 µg/kg) and one (147.79 µg/kg) of the 80 samples, respectively. Finally, the estimated dietary intakes (EDIs) of the detected mycotoxins, among the Valencian population, were calculated and the health risk assessment was performed. The calculated EDIs were all below the established tolerable daily intake values (TDI)

En este trabajo, 80 muestras comerciales de pan rallado, compradas en diferentes supermercados ubicados en Valencia (España), fueron investigadas por la presencia de 11 micotoxinas legisladas. Sólo 9 muestras evidenciaron la presencia de las micotoxinas legisladas. Los compuestos detectados fueron: ocratoxina A (OTA), zearalenona (ZEA), toxina T-2 (T-2) y toxina HT-2 (HT-2). La incidencia de OTA fue de 3.75% con concentraciones que van desde 1.50 a 6.75 µg / kg. Una muestra mostró un nivel de contaminación más alto que el máximo legislado en Europa para OTA. Tres muestras se contaminaron con ZEA en concentraciones que variaban de 64.32 a 449.21 µg / kg; todos los valores fueron superiores al máximo permitido por la legislación. T-2 y HT-2 se detectaron en dos (18.25-2700,48 µg / kg) y una (147.79 µg / kg) de las 80 muestras, respectivamente. Finalmente, se calcularon las ingestas dietéticas estimadas (EDI) de las micotoxinas detectadas, entre la población valenciana, y se realizó la evaluación del riesgo para la salud. Los EDI calculados estaban todos por debajo de los valores de ingesta diaria tolerable (TDI) establecidos

Occurrence, toxicity, bioaccessibility and mitigation strategies of beauvericin, a minor Fusarium mycotoxin.

Emerging Fusarium mycotoxins include the toxic secondary metabolites fusaproliferin, enniatins, beauvericin (BEA), and moniliform. BEA is produced by some entomo- and phytopathogenic Fusarium species and occurs naturally on corn and corn-based foods and feeds infected by Fusarium spp. BEA has shown various biological activities (antibacterial, antifungal, and insecticidal) and possesses toxic activity, including the induction of apoptosis, increase cytoplasmic calcium concentration and lead to DNA fragmentation in mammalian cell lines. Cereals food processing has an important effect on mycotoxin stability, leading to less-contaminated food compared to the raw materials. Different industrial processes have shown to be effective practices to reduce BEA contents due to thermal food processing applied, such as cooking, boiling, baking, frying, roasting and pasteurization. Some studies demonstrated the capacity of lactic acid bacteria to reduce the presence of the BEA in model solution and in food chain through fermentation processes, modifying this mycotoxin in a less toxic derivate. Prebiotic and probiotic ingredient can modulate the bioaccessibility of BEA reducing the risk of intake of this minor Fusarium mycotoxin. This review summarizes the existing data on occurrence, toxicity and especially on BEA reduction strategies in food and feed such as chemical reduction, biocontrol and food processing.

Reaction of zearalenone and α-zearalenol with allyl isothiocyanate, characterization of reaction products, their bioaccessibility and bioavailability in vitro.

This study investigates the reduction of zearalenone (ZEA) and α-zearalenol (α-ZOL) on a solution model using allyl isothiocyanate (AITC) and also determines the bioaccessibility and bioavailability of the reaction products isolated and identified by MS-LIT. Mycotoxin reductions were dose-dependent, and ZEA levels decreased more than α-ZOL, ranging from 0.2 to 96.9% and 0 to 89.5% respectively, with no difference (p⩽0.05) between pH 4 and 7. Overall, simulated gastric bioaccessibility was higher than duodenal bioaccessibility for both mycotoxins and mycotoxin-AITC conjugates, with duodenal fractions representing ⩾63.5% of the original concentration. Simulated bioavailability of reaction products (α-ZOL/ZEA-AITC) were lower than 42.13%, but significantly higher than the original mycotoxins. The cytotoxicity of α-ZOL and ZEA in Caco-2/TC7 cells was also evaluated, with toxic effects observed at higher levels than 75µM. Further studies should be performed to evaluate the toxicity and estrogenic effect of α-ZOL/ZEA-AITC.

In vitro antifungal activity of allyl isothiocyanate (AITC) against Aspergillus parasiticus and Penicillium expansum and evaluation of the AITC estimated daily intake.

Isothiocyanates (ITCs) are natural compounds derived from cruciferous vegetables produced by enzymatic conversion of metabolites called glucosinolates. They are potentially useful antimicrobial compounds for food applications have been shown to be promising agents against cancer in human cell culture, animal models, and in epidemiological studies. In this study, the antifungal activity of the allyl isothiocyanate (AITC) was evaluated on two mycotoxigenic fungi as Aspergillus parasiticus and Penicillium expnsum, aflatoxins (AFs) and patulin (PAT) producers, employing an assay on solid medium. Also an approximation of the risk evaluation associated to the intake of food treated with the AITC to reduce the risk of fungi spoilage has been evaluated. On solid medium and after 20 days incubation the strain of Penicillium expansum was inhibited with AITC quantities highest than 50 mg, whereas the strain of A. parasiticus was sensible to AITC doses highest than 5 mg. The analysis of the risk assessment associated to the intake of several food classes treated with the bioactive compound AITC to prevent fungi spoilage evidenced that this product can be considered as safe due that the estimated daily intakes (EDIs) are always lower than the AITC Admissible Daily intake (ADI).

Influence of prebiotics, probiotics and protein ingredients on mycotoxin bioaccessibility.

The aim of this study was to investigate the influence of prebiotic compounds (cellulose and inulin), food ingredients (milk whey, ß-lactoglobulin and calcium caseinate) and several probiotic microorganisms on the bioaccessibility of beauvericin (BEA), enniatins (ENs A, A1, B, B1), deoxynivalenol (DON) and zearalenone (ZEA) present in wheat crispy bread produced with wheat flour previously fermented with F. tricinctum, F. culmorum and G. zeae. The bioaccessibility of mycotoxins was determined by a dynamic simulated gastrointestinal digestion system, imitating the human digestive physiological conditions of the gastrointestinal tract. Mycotoxins were determined in the simulated intestinal fluids by liquid chromatography-tandem mass spectrometry (LC-MS/MS). EN bioaccessibility ranged from 15.1 to 30.6%, whereas the values evidenced for BEA ranged from 12 to 19%. DON showed bioaccessibility data ranging from 0.8 to 5.6% whereas for ZEA the data evidenced ranged from 26 to 44%. The bioaccessibility reduction evidenced using probiotic microorganisms for the mycotoxins studied ranged from 21 to 27.1% for ENs, from 29 to 39.7% for DON, from 41 to 57% for ZEA and from 6.6 to 10.5% for BEA. The addition of prebiotic and bioactive microorganisms decreased the bioaccessibility of mycotoxins, with a concentration-dependent behavior, thus being a potential strategy for reducing human exposure to these minor mycotoxins.

Biosynthesis of beauvericin and enniatins in vitro by wheat Fusarium species and natural grain contamination in an area of central Italy.

Contamination of wheat grain by beauvericin (BEA) and enniatins (ENs) is a global emerging mycotoxicological food problem. In this study, strains of Fusarium avenaceum (FA), Fusarium poae (FP), Fusarium equiseti and Fusarium sporotrichioides, all potential BEA and EN producers, isolated from 162 grain samples of durum and soft wheat harvested in 2009 and 2010 collected in an area of central Italy, were preliminarily screened for the presence of the esyn1 gene, encoding the multifunctional enzyme enniatin-synthetase for the detection of potential hexadepsipeptide-producing isolates. All positive isolates were tested for their ability to biosynthesize BEA and ENs in vitro. In addition, all wheat samples were investigated for the natural presence of BEA and ENs (ENA, ENA1, ENB, ENB1). All FA and FP strains resulted to be positive for the presence of the esyn1 gene. All FA strains showed the ability to biosynthesize ENs in vitro but not BEA. Conversely, all FP strains resulted to be BEA producers and some of them co-biosynthesized ENs. A remarkable presence of "emerging" mycotoxins was found in the grains, particularly ENs. Co-contamination by BEA and ENs also occurred. This study gives an important contribution to assess the risk posed by mycotoxigenic fungi and their mycotoxins in food.

Cytotoxic and interactive effects of zearalenone, alpha-zearalenol and beta-zearalenol and formation of metabolites in HepG2 cells / Citotoxicidad, formación de metabolitos e interacción entre zearalenona, alpha-zearalenol y beta-zearalenol en células HepG2

Zearalenone (ZEA) is a secondary metabolite of Fusarium fungi. ZEA is a non-steroidal estrogenic mycotoxin which is rapidly absorbed and metabolized to α-zearalenol (α-ZOL) and β-zearalenol (β-ZOL) in the liver; therefore mixtures of these mycotoxins may be simultaneously present in biological systems and cause human health risk. The objectives of this study were: a) to compare the cytotoxicity of ZEA, α-ZOL and β-ZOL alone or in combination on human hepatoma (HepG2) cells using the MTT assay after 24, 48 and 72h of exposure, and b) to evaluate the interactions of these mycotoxins mixtures in HepG2 cell lines by the isobologram analysis. The IC50 values obtained for individual mycotoxins range from 70.0 to >100.0 µM, from 20.6 to 26.0 µM and from 38.4 to >100.0 µM in HepG2 cells for ZEA, α-ZOL and β-ZOL, respectively. Isobologram analysis provides a combination index (CI) value to determine the type of interaction that occurs. The interactions of ZEA and its metabolites showed slightly synergism (CI from 0.34±0.10 to 0.69±0.22) followed by additive effect (CI from 0.97±0.20 to 2.61±2.15) and turned into antagonism (CI from 1.29±0.18 to 7.77±2.27). The concentration of ZEA and its metabolites was determined with liquid chromatography coupled to the mass spectrometer detector-linear ion trap (LC-MS-LIT). No conversion of ZEA in α-ZOL and β-ZOL was detected. However other degradation products were detected (AU)

La zearalenona (ZEA) es un metabolito secundario producido por hongos del género Fusarium. ZEA es una micotoxina estrogénica no esteroidea que se metaboliza rápidamente en el hígado a α-zearalenol (α-ZOL) y β-zearalenol (β-ZOL); por lo tanto, mezclas de estas micotoxinas pueden estar presentes simultáneamente en un sistema biológico y causar un riesgo para la salud humana. Los objetivos de este estudio fueron: a) comparar la citotoxicidad de la ZEA, α-ZOL y β-ZOL de forma individual y en combinación en células hepáticas humanas (HepG2) usando el ensayo MTT tras una exposición de 24, 48 y 72h y b) evaluar la interacción de las mezclas de estas micotoxinas en células HepG2 mediante el análisis de las isobolas. Los valores de IC50 obtenidos en células HepG2 con las micotoxinas individuales van desde 70,0 a >100,0 µM, de 20,6 a 26,0 µM y de 38,4 a >100 µM para ZEA, α-ZOL y β-ZOL, respectivamente. El método de las isobolas proporciona el índice de combinación (IC) con el que se determina el tipo de interacción que se produce entre las micotoxinas. La interacción entre la ZEA y sus metabolitos mostró un ligero sinergismo (CI de 0,34±0,10 a 0,69±0,22), seguido de un efecto aditivo (CI de 0,97±0,20 a 2,61±2,15) que se acabó en antagonismo (CI de 1,29±0,18 a 7,77±2,27) dependiendo de la concentración y tiempo de exposición. La concentración de ZEA y sus metabolitos se determinó con cromatografía líquida acoplada a espectrometría de masas con trampa de iones lineal (LC-MS-LIT). No se detectó ninguna conversión de ZEA en α-ZOL y β-ZOL. Sin embargo se detectaron otros productos de degradación (AU)

Antibacterial activity of the emerging Fusarium mycotoxins enniatins A, A1, A2, B, B1, and B4 on probiotic microorganisms.

Enniatins (ENs) are secondary metabolites produced by several Fusarium strains, chemically characterized as N-methylated cyclohexadepsipeptides. These compounds are known to act as antifungal and antibacterial agents, but they also possess anti-insect and phytotoxic properties. In this study, the antimicrobial effect of pure fractions of the bioactive compounds ENs A, A1, A2, B, B1, and B4 was tested towards nine probiotic microrganisms, twenty-two Saccharomyces cerevisiae strains and nine Bacillus subtilis strains. Antimicrobial analyses were carried out the disc-diffusion method using ENs concentrations ranging from 0.2 to 20,000 ng. Plates were incubated for 24 h at 37 °C before reading the diameter of the inhibition spots. ENs A, A1, A2, B, B1 and B4, were active against several microorganisms with inhibition halos ranging from 3 to 12 mm in diameter. The most active mycotoxin was the EN A1, which reduced the microbial growth of 8 strains at the dose of 20,000 ng, with inhibition spots sized between 8 and 12 mm. ENs B and B4 showed no antimicrobial activity towards the microorganisms tested at doses up to 20,000 ng per disc.

A chemical approach for the reduction of beauvericin in a solution model and in food systems.

Beauvericin (BEA) is a bioactive compound produced by the secondary metabolism of several Fusarium strains with a strong antibacterial, antifungal, and insecticidal activities. This study evaluated the reduction of BEA added at 25 mg/kg in phosphate buffer saline (PBS) solutions at pH of 4, 7 and 10, or to different cereal products (kernels and flours) by the bioactive compounds phenyl isothiocyanate (PITC) and benzyl isothiocyanate (BITC). The concentration of the mycotoxin was evaluated using liquid chromatography coupled to the diode array detector (LC-DAD). In solution, BEA reduction ranged from 9% to 94% on a time-dependent fashion and lower pH levels resulted in higher BEA reduction. Cereal kernels and flours treated with gaseous PITC and BITC (50, 100 and 500 µL/L) presented BEA reduction from 9% to 97% and was dose-dependent. Among the crops, corn was the vehicle where BEA was mostly affected by the action of the ITCs, followed by wheat and rice, and lastly barley. Overall, PITC caused higher reduction of BEA and should be chosen over BITC as a fumigant to decrease the levels of this mycotoxin in grains and flours.

Degradation study of enniatins by liquid chromatography-triple quadrupole linear ion trap mass spectrometry.

Enniatins A, A1, B and B1 (ENs) are mycotoxins produced by Fusarium spp. and are normal contaminants of cereals and derivate products. In this study, the stability of ENs was evaluated during food processing by simulation of pasta cooking. Thermal treatments at different incubation times (5, 10 and 15 min) and different pH (4, 7 and 10) were applied in an aqueous system and pasta resembling system (PRS). The concentrations of the targeted mycotoxins were determined using liquid chromatography coupled to tandem mass spectrometry. High percentages of ENs reduction (81-100%) were evidenced in the PRS after the treatments at 5, 10 and 15 min of incubation. In contrast to the PRS, an important reduction of the ENs was obtained in the aqueous system after 15 min of incubation (82-100%). In general, no significant differences were observed between acid, neutral and basic solutions. Finally, several ENs degradation products were identified using the technique of liquid chromatography-triple quadrupole linear ion trap mass spectrometry.

Ciclohexadespipeptide beauvericin degradation by different strains of Saccharomyces cerevisiae.

The interaction between the mycotoxin beauvericin (BEA) and 9 yeast strains of Saccharomyces cerevisiae named LO9, YE-2, YE5, YE-6, YE-4, A34, A17, A42 and A08 was studied. The biological degradations were carried out under aerobic conditions in the liquid medium of Potato Dextrose Broth (PDB) at 25°C for 48 h and in a food/feed system composed of corn flour at 37°C for 3 days, respectively. BEA present in fermented medium and corn flour was determined using liquid chromatography coupled to the mass spectrometry detector in tandem (LC-MS/MS) and the BEA degradation products produced during the fermentations were determined using the technique of the liquid chromatography coupled to a linear ion trap (LIT). Results showed that the S. cerevisiae strains reduced meanly the concentration of the BEA present in PDB by 86.2% and in a food system by 71.1%. All the S. cerevisiae strains used in this study showed a significant BEA reduction during the fermentation process employed.

Reduction of the enniatins A, A1, B, B1 by an in vitro degradation employing different strains of probiotic bacteria: identification of degradation products by LC-MS-LIT.

The degradation of the Fusarium mycotoxins ENs by 9 bacterial strains characteristic of the gastrointestinal tract like Bb. longum, Bb. bifidum, Bb. breve, Bb. adolescentes, Lb. rhamnosus, Lb. casei-casei, S. termofilus, Lb. ruminis, Lb. casei and twenty two strains of Saccharomyces cerevisiae was studied. The fermentations were carried out in the liquid medium of De Man Rogosa Sharpe (MRS) under anaerobic conditions for Bifidobacteria Streptococcus and Lactobacillus, and in Potato Dextrose Broth (PDB) for Saccharomyces strains, during 48 h. The degradation of the bioactive compounds ENs was also studied in a food system composed by wheat flour naturally contaminated by ENs through fermentation by a strain of Fusarium tricinctum. The determination of the ENs in the fermentation mediums was performed using the technique of the liquid chromatography coupled to the mass spectrometry detector in tandem (LC-MS/MS), whereas the identification of the degradation products produced by microbial fermentation was carried out using the technique of the LC coupled to the linear ion trap (LIT). All the bacteria analyzed in this study showed a significant ENs reduction in vitro during the fermentation processes, with degradation data ranging from 5 to the 99%. In the food system, the ENs degradation data evidenced ranged from 1.3 to 49.2%. Also three ENs degradation products were identified.

Study of the chemical reduction of the fumonisins toxicity using allyl, benzyl and phenyl isothiocyanate in model solution and in food products.

Fumonisins (FBs) are bioactive compounds produced by several strains of Fusarium spp. which contain a polyketide structure similar to sphinganine. These mycotoxins contain a free amino group that could work as an electron donor and react with the electrophile carbon present within the isothiocyanate (ITC) group. The objective of this study was to determine the effect of ITCs (allyl, benzyl and phenyl) on the stability of FB(1), FB(2) and FB(3). Firstly, PBS solutions at three pH levels (4, 7 and 9) were prepared and added with pairs of one FB (1 mg/L) plus one ITC (1 mg/L). Then, gaseous ITC was used to fumigate corn kernels and corn flour contaminated with FBs produced by Gibberella moniliformis CECT 2987 in situ. Mycotoxin levels were evaluated using liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS), while products formed from the reaction of FBs and ITCs were examined by liquid chromatography coupled to mass spectrometry-linear ion trap (LC-MS-LIT). The reduction of FB(1) and FB(2) in solution ranged from 42 to 100% on a time-dependent manner. This variance was greatly influenced by pH. In general, lower pH levels eased the reaction between ITCs and FBs. ITC fumigation treatment (50, 100 and 500 µL/L) was able to reduce 53-96% of FB(1) levels, 29-91% of FB(2) and 29-96% of FB(3). Four reaction products between the bioactive compounds employed in this study were identified, corresponding to FB + ITC conjugates.

Chemical reduction of the mycotoxin beauvericin using allyl isothiocyanate.

Beauvericin (BEA) is a bioactive compound produced by the secondary metabolism of several Fusarium strains and known to have various biological activities. This study investigated the reduction of BEA present in the concentration of 25mg/kg on a solution model (phosphate buffer saline at pH 4 and 7) and in wheat flour using allyl isothiocyanate (AITC) as a reactant. The concentration of the mycotoxin studied was evaluated using liquid chromatography coupled to the diode array detector (LC-DAD), whereas adducts formed between the BEA and AITC were examined by liquid chromatography coupled to mass spectrometry-linear ion trap (LC-MS-LIT). In solution, BEA reduction ranged from 20% to 100% on a time-dependent fashion and no significant differences were evidenced between the two pH levels employed. In the food system composed by wheat flour treated with gaseous AITC (50, 100 and 500 µL/L), the BEA reduction varied from 10% to 65% and was dose-dependent. Two reaction products between the bioactive compounds employed in this study were identified, corresponding to BEA conjugates containing one or two AITC molecules.